Fallers for textile machines



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m h 9 Q United States Patent 3,344,481 FALLERS FOR TEXTILE MACHINESMoore Hill, Belfast, Northern Ireland, assignor to James Mackie & SonsLimited, Belfast, Northern Ireland, a British company Filed June 24,1965, Ser. No. 466,558 Claims priority, application Great Britain, June26, 1964, 26,571/ 64 7 Claims. (Cl. 19-129) ABSTRACT OF THE DISCLOSURE Afaller for a textile machine having a central portion of substantiallyuniform depth terminating at each end in a head portion of greater depthand in which the pins are supported in a body of rubber located in alongitudinal slot passing through the depth of the faller and extendingbeyond the ends of'the portion of uniform depth and into the headportions, the extension at each end having a smaller average width thanthe remainder of the slot.

This invention relates to a faller for textile machines of the kinddescribed in Patent No. 3,057,021 that is to say in which the pins arecarried by a layer of rubber or other relatively soft material locatedin a slot between side members. The central portion of such fallers isof substantially uniform depth and terminates at each end in a headportion which is of greater depth so as to cooperate with the drivingmechanism of the machine in which the fallers are used. During operationfallers are subjected to varying mechanical stresses largely occasionedby the transfer from one slide to the other. In addition the drag of thefibres being processed on the pins of the faller produces a considerablebending or bowing action at right angles to the axis of the pins. Thesedifferent types of stresses lead to fatigue in the fallers and it isfound that the effects of the fatigue are most marked in the region ofthe end of the slot between the side members which contains theresilient mounting for the pins. Fallers constructed in the waydescribed above are particularly resistant to such fatigue stresses butwith the ever-increasing demands of modern production conditionsparticularly the very high speeds demanded and also the ability of amachine to run for long periods 'without the need for any replacement,even the small number of failures resulting from such construction leadto the desire for improvement.

According to the present invention the slot holding the rubber-likematerial in which the pins are supported extends beyond the ends of theportion of uniform depth and thus terminates in a greater depth of bar.This extension of the slot at each end serves to transfer theconcentration of fatigue stresses to a greater depth of metal so thatthe bar is better able to withstand such stresses. It is found that thismodification of the construction results in a significant reduction inthe number of failures of fallers under any given operating conditions.

Preferably the extension at each end of the slot has a smaller averagewidth than the remainder. Thus the extension may be parallel-sided andof smaller width than the remainder of the slot or alternatively theextension may taper gradually from the full width of the remainder ofthe slot. In this way the change of section of the bar is efiected instages thus leading to a greater dispersion of the fatigue stresses. Aspreviously described these fatigue stresses are caused at least in partby bowing of the faller due to the drag of the fibres being processed.This bowing can be reduced by an increase in the stiff- 3,344,481Patented Oct. 3, 1967 ness of the bar and for this purpose at least oneof the side members is made thicker over the region of its midheight.For purposes of symmetry and ease of manufacture this thickening maytake the form of a longitudinal stilfening rib along the inner side ofeach side member.

The side members are preferably integral with the head portions at eachend and this may be achieved either by milling the central slot from asolid bar or by means of a precision casting operation. Alternatively,however, the side members may be secured to the head portions asdescribed in Patent No. 3,057,021.

Machining of the central slot lends itself particularly well to aconstruction in which the extension of the slot at each end is ofreduced width and parallel sided and in which each side member is formedwith a longitudinal stiffening rib. For this purpose the solid bar maybe machined both from above and below to form first slots each of depthslightly less than half that of the bar so that a layer of material isleft between them. This residual central portion of the bar is thenmachined to form a second slot of lesser width than the first slots andextending beyond their ends. The parts of the central portion which areleft after this final machining operation constitute the stiffening ribsand the end portions of the narrower slot constitute the extensions ofthe main slot.

Constructions in accordance with the invention will now be described byway of example with reference to the accompanying drawings in which:

FIGURE 1 is an elevation partly in section;

FIGURE 2 is a plan view' corresponding to FIGURE 1 but shown in sectionalong the line IIII in FIG- URE 1;

FIGURE 3 is a sectional end view seen along the line IIIIII in FIGURE 1;

FIGURE 4 is an elevation of the end portion of an alternativeconstruction; and,

FIGURE 5 is a sectional end view seen on the line VV in FIGURE 4.

Turning first to FIGURE 1 the faller illustrated comprises a centralportion 1 of uniform depth terminating at each end in a head portion 2.Each head portion has a groove 3 for cooperation with guides on themachine in which it is to be used and inclined end portions 4 forengagement with the screw feed mechanism. As can be seen from thedrawing the head portions 2 are considerably deeper than the centralportion 1. The central portion 1 is formed with a longitudinal slotindicated generally as 6 and which as best seen from FIGURE 3 comprisesupper and lower portions 7 and 8 respectively which are both broaderthan a central portion 9. The broader portions 7 and 8 both terminate atpoints shown as 10 approximately level with the end of the centralportion 1. The narrower slot 9, however, extends beyond this to a pointshown as 11 so as to terminate in a depth of faller which is greaterthan that of the central portion 1. The termination of the slot in thisportion of increased depth has the effect already described oftransferring the concentration of fatigue stresses to this point, andthe fact that the extension of the slot past the point 10 is narrowerthan the main body of the slot means that the change of section isaccomplished in two stages, thus leading to further dispersion of thefatigue stresses.

The pins shown in dotted lines as 15 are held by a body of rubber orsimilar rubber-like material which occupies the Whole of the slot 6,being covered by a metal strip 20, and which is omitted from the drawingfor simplicity. The effect of this mounting however, is the same asdescribed in Patent No. 3,057,021 in that although it provides amplesupport for the pins during operation it nevertheless enables them to bereplaced Without difiiculty when required.

The faller illustrated in FIGURES 1 to 3 is most conveniently producedby milling the slot 6 from a solid bar. For this purpose the slots 7 and8 are first milled from above and below respectively to leave a residualcentral portion in the region of the slot 9. These two slots areextended at the ends as far as the points 10 already referred to. Anarrower cutter is then used to mill the slot 9 through the residualcentral portion and this slot is extended at the ends to the points 11as already described.

The fact that the central slot 9 is narrower than the slots 7 and 8means that longitudinal stiffening ribs 16 and 17 are left on the innerfaces of the two side members 18 and 19 defined by the central slot 6.The effect of these two ribs is to stiifen the assembly as a whole andthus to reduce bowing of the faller which in itself is a major factorleading to fatigue. The main body of rubber holding the pins 15 inposition is located in the slots 7 and 8 but these two portions areconnected together by a thinner body of rubber passing through the slot9 and this slot must therefore be sufficiently wider than the pins 15 toallow the rubber to be continuous and thus to exert an adequate grip onthe pins 15.

FIGURES 4 and illustrate an alternative form of construction, the natureof which is best seen from the sectional view of FIGURE 5. Once againthe central slot 6 is milled from a solid bar, but in this case atapered milling cutter as shown in dotted lines at 22 is used in placeof the parallel-sided cutter used for the slots 7 and 8. Upper and lowerslots 23 and 24 are milled by means of this cutter and are extendedsufficiently far to meet at the centre. These slots, therefore, tapertowards the centre of the bar so that each of the side members 18 and 19is thicker at its mid height as indicated as 25 and 26. This thickeninghas an effect equivalent to that of the stiffening ribs 16 and 17 inreducing bowing of the faller.

In addition the ends of the slots 23 and 24, which are shown in FIGURE 4as 28 and 29 respectively, taper from the full width of slot at a point30, which is approximately level with the end of the central portion 1,to a narrower width as determined by the shape of the cutter 22. Inother words the extension of the central slot 6 is tapered so that thechange of section at this point occurs gradually and thus thereforeassists the distribution of the fatigue stresses. Owing to the fact thatthe milling cutter does not pass right through the bar but merelymachines the slots 23 and 24 from above and below respectively, asindicated by the dotted circular arcs 23' and 24' in FIGURE 4, anapproximately triangular portion 32 is left at each end of the slot andmust be removed by a subsequent operation e.g. by broaching.

I claim:

1. A faller for a textile machine, said faller comprising a body havinga central portion of substantially uniform depth terminating at each endin a head portion of greater depth, said body being formed with alongitudinal slot passing through the depth of said body and extendingbeyond the ends of said portion of substantially uniform depth and intothe head portions, a mounting of rubberlike elastomer secured in saidslot and a plurality of pins extending through and supported by saidmounting.

2. A faller according to claim 1, in which the extension at each end ofsaid slot has a smaller average width than the remainder.

3. A faller according to claim 1, in which the extension at each end ofsaid slot is parallel-sided and is narrower than the remainder.

4. A faller according to claim 1, in which the extension at each end ofsaid slot tapers towards its end.

5. A faller according to claim 1 in which said central portion of saidbody is integral with said head portions.

6. A faller for a textile machine, said faller comprising a body havinga central portion of substantially uniform depth terminating at each endin a head portion of greater depth, said body being formed with alongitudinal slot passing through the depth of said body and definingspaced side members, at least one of said side members being thickerover the region of its mid-height, a mounting of rubber-like elastomersecured in said slot and a plurality of pins extending through andsupported by said mounting.

7. A faller according to claim 6, in which each said side member has alongitudinal stiffening rib along its inner side formed by the thickermid-height portion.

References Cited FOREIGN PATENTS 4/1958 Belgium. 9/1955 Great Britain.

1. A FALLER FOR A TEXTILE MACHINE, SAID FALLER COMPRISING A BODY HAVINGA CENTRAL PORTION OF SUBSTANTIALLY UNIFORM DEPTH TERMINATING AT EACH ENDIN A HEAD PORTION OF GREATER DEPTH, SAID BODY BEING FORMED WITH ALONGITUDINAL SLOT PASSING THROUGH THE DEPTH OF SAID BODY AND EXTENDINGBEYOND THE ENDS OF SAID PORTION OF SUBSTANTIALLY UNIFORM DEPTH AND INTOTHE HEAD PORTIONS, A MOUNTING OF RUBBERLIKE ELASTOMER SECURED IN SAIDSLOT AND A PLURALITY OF PINS EXTENDING THROUGH AND SUPPORTED BY SAIDMOUNTING.